George Clooney has said he's determined to keep breaking boundaries with the films he makes.

The Hollywood heartthrob has just directed his fourth film, political thriller The Ides of March and insists he isn't going to shy away from using his current influence to make films "that keep pushing the envelope".

George said: "When they give you the keys to the toy box, you want to use it as much as you possibly can until they take them away. And they will, eventually."

His 2005 film Good Night, And Good Luck earned him an Oscar nomination but The Descendants star doesn't take anything for granted.

He said: "In terms of doing things for others, I've had a lot of luck in my life.

"There were equally good, if not better, actors in acting class than me. Luck is only good if you spread it around.

"I don't think of that as a great thing to do; I think that's what you're supposed to do."

And despite his success an actor, George wants to focus on being a director.

He said: "The older you get, the less roles there are to play and I want to be part of this business for a long time."